Systems for the automated and contained filling of powders into IBCs (intermediate bulk containers) including “thro lid filling systems” and “split butterfly valve systems” have been in use for some years, particularly in the pharmaceutical industry where maintaining product purity and protecting operators against active and/or toxic powders are two major requirements. Such systems include devices for the automated removal and refitting of the container lid inside the powder process itself. These devices are often very sensitive and their reliability is to some extent dependant on regular system cleaning and maintenance. They are also extremely complex and expensive. However, there is increasing demand for automated lid removal systems in other industries e.g. food manufacturing, to increase productivity, reduce labour costs and to meet increasing hygiene standards. In these applications with increased frequency of use and reduced frequency of cleaning the existing methods of lid removal suffer from a number of limitations which render them unfeasible.
One existing method used for automated lid removal includes use of a vacuum cup. The cup makes contact with the top surface of the lid and vacuum is generated in order to retain the lid against the filing system valve during powder transfer. This method is used in the Matcon™ Containment Transfer System. Characteristics include:                The generated vacuum directly retains the lid in position, i.e. a “live vacuum”.        If surfaces are allowed to accumulate dust, the level of vacuum force can reduce.        Dust can also be drawn into the vacuum line causing blockage and further reduction of vacuum force.        The System is dependent on the vacuum level being sufficient to carry the weight of the lid, therefore it is not inherently fail-safe, i.e. if the vacuum should completely fail the lid is dropped.        After completion of material transfer, the lid is refitted to the container inlet by simple release of vacuum and is lowered to the correct position by gravity alone.        A more positive lid replacement can be achieved by introducing positive pressure in the vacuum line but this risks emitting a cloud of dust to the working environment and in a failure mode, could over pressurise the process equipment.        
Other methods of lid retention include various forms of mechanical locking devices. Mechanical grabbing devices include sliding lock pins or bayonet devices, engaging into holes or grooves in the lid, and are effective lid retainers, but in simplest form they lack the positive up-force needed to fully seal the lid to the fill valve. They also suffer from dust ingress into the various holes and crevices, leading to cross contamination of powders being handled, plus cleaning difficulty, functionality and corrosion problems.
It is an object of the invention to seek to mitigate problems such as these.